Two-sided Certification: The market for Rating Agencies

Certifiers contribute to the sound functioning of markets by reducing a symmetric information. They, however, have been heavily criticized during the 2008-09 financial crisis. This paper investigates on which side of the market a monopolistic profit-maximizing certifier offers his service. If the seller demands a rating, the certifier announces the product quality publicly, whereas if the buyer requests a rating it remains his private information. The model shows that the certifier offers his service to sellers and buyers to maximize his own profit with a higher share from the sellers. Overall, certifiers increase welfare in specific markets. Revenue shifts due to the financial crisis are also explained

Two-sided Certification: The market for Rating Agencies

Certifiers contribute to the sound functioning of markets by reducing asymmetric information. They, however, have been heavily criticized during the 2008-09 financial crisis. This paper investigates on which side of the market a monopolistic profit-maximizing certifier offers his service. If the seller demands a rating, the certifier announces the product quality publicly, whereas if the buyer requests a rating it remains his private information. The model shows that the certifier offers his service to sellers and buyers to maximize his own profit with a higher share from the sellers. Overall, certifiers increase welfare in specific markets. Revenue shifts due to the financial crisis are also explained.Certification, Rating Agencies, Asymmetric Information, Financial Markets

Multimodal Dependent Type Theory

We introduce MTT, a dependent type theory which supports multiple modalities. MTT is parametrized by a mode theory which specifies a collection of modes, modalities, and transformations between them. We show that different choices of mode theory allow us to use the same type theory to compute and reason in many modal situations, including guarded recursion, axiomatic cohesion, and parametric quantification. We reproduce examples from prior work in guarded recursion and axiomatic cohesion, thereby demonstrating that MTT constitutes a simple and usable syntax whose instantiations intuitively correspond to previous handcrafted modal type theories. In some cases, instantiating MTT to a particular situation unearths a previously unknown type theory that improves upon prior systems. Finally, we investigate the metatheory of MTT. We prove the consistency of MTT and establish canonicity through an extension of recent type-theoretic gluing techniques. These results hold irrespective of the choice of mode theory, and thus apply to a wide variety of modal situations

Anisotropy, Phonon Modes, and Free Charge Carrier Parameters in Monoclinic β-Gallium Oxide Single Crystals

We derive a dielectric function tensor model approach to render the optical response of monoclinic and triclinic symmetry materials with multiple uncoupled infrared and far-infrared active modes. We apply our model approach to monoclinic β-Ga2O3 single-crystal samples. Surfaces cut under different angles from a bulk crystal, (010) and (2̅01), are investigated by generalized spectroscopic ellipsometry within infrared and far-infrared spectral regions. We determine the frequency dependence of 4 independent β-Ga2O3 Cartesian dielectric function tensor elements by matching large sets of experimental data using a point-by-point data inversion approach. From matching our monoclinic model to the obtained 4 dielectric function tensor components, we determine all infrared and far-infrared active transverse optic phonon modes with Au and Bu symmetry, and their eigenvectors within the monoclinic lattice. We find excellent agreement between our model results and results of density functional theory calculations. We derive and discuss the frequencies of longitudinal optical phonons in β-Ga2O3. We derive and report density and anisotropic mobility parameters of the free charge carriers within the tin-doped crystals. We discuss the occurrence of longitudinal phonon plasmon coupled modes in β-Ga2O3 and provide their frequencies and eigenvectors. We also discuss and present monoclinic dielectric constants for static electric fields and frequencies above the reststrahlen range, and we provide a generalization of the Lyddane-Sachs-Teller relation for monoclinic lattices with infrared and far-infrared active modes.We find that the generalized Lyddane-Sachs-Teller relation is fulfilled excellently for β-Ga2O3

Coexisting Cyclic Parthenogens Comprise a Holocene Species Flock in Eubosmina

Background: Mixed breeding systems with extended clonal phases and weak sexual recruitment are widespread in nature but often thought to impede the formation of discrete evolutionary clusters. Thus, cyclic parthenogens, such as cladocerans and rotifers, could be predisposed to ‘‘species problems’ ’ and a lack of discrete species. However, species flocks have been proposed for one cladoceran group, Eubosmina, where putative species are sympatric, and there is a detailed paleolimnological record indicating a Holocene age. These factors make the Eubosmina system suitable for testing the hypotheses that extended clonal phases and weak sexual recruitment inhibit speciation. Although common garden experiments have revealed a genetic component to the morphotypic variation, the evolutionary significance of the morphotypes remains controversial. Methodology/Principal Findings: In the present study, we tested the hypothesis of a single polymorphic species (i.e., mixing occurs but selection maintains genes for morphology) in four northern European lakes where the morphotypes coexist. Our evidence is based on nuclear DNA sequence, mitochondrial DNA sequence, and morphometric analysis of coexisting morphotypes. We found significant genetic differentiation, genealogical exclusivity, and morphometric differentiation for coexisting morphotypes. Conclusions: We conclude that the studied morphotypes represent a group of young species undergoing speciation wit

Global 3-D Simulations of the Triple Oxygen Isotope Signature Δ17O in Atmospheric CO2

The triple oxygen isotope signature Δ¹⁷O in atmospheric CO₂, also known as its “¹⁷O excess,” has been proposed as a tracer for gross primary production (the gross uptake of CO₂ by vegetation through photosynthesis). We present the first global 3-D model simulations for Δ¹⁷O in atmospheric CO₂ together with a detailed model description and sensitivity analyses. In our 3-D model framework we include the stratospheric source of Δ¹⁷O in CO₂ and the surface sinks from vegetation, soils, ocean, biomass burning, and fossil fuel combustion. The effect of oxidation of atmospheric CO on Δ¹⁷O in CO2 is also included in our model. We estimate that the global mean Δ¹⁷O (defined as Δ¹⁷O = ln( ¹⁷O + 1) − RL · ln( ¹⁸O + 1) with RL = 0.5229) of CO₂ in the lowest 500 m of the atmosphere is 39.6 per meg, which is ∼20 per meg lower than estimates from existing box models. We compare our model results with a measured stratospheric Δ¹⁷O in CO₂ profile from Sodankylä (Finland), which shows good agreement. In addition, we compare our model results with tropospheric measurements of Δ¹⁷O in CO₂ from Göttingen (Germany) and Taipei (Taiwan), which shows some agreement but we also find substantial discrepancies that are subsequently discussed. Finally, we show model results for Zotino (Russia), Mauna Loa (United States), Manaus (Brazil), and South Pole, which we propose as possible locations for future measurements of Δ¹⁷O in tropospheric CO₂ that can help to further increase our understanding of the global budget of Δ¹⁷O in atmospheric CO₂

D-cycloserine augmentation of exposure-based cognitive behavior therapy for anxiety, obsessive-compulsive, and posttraumatic stress disorders: a systematic review and meta-analysis of individual participant data

Importance: Whether and under which conditions D-cycloserine (DCS) augments the effects of exposure-based cognitive behavior therapy for anxiety, obsessive-compulsive, and posttraumatic stress disorders is unclear. Objective: To clarify whether DCS is superior to placebo in augmenting the effects of cognitive behavior therapy for anxiety, obsessive-compulsive, and posttraumatic stress disorders and to evaluate whether antidepressants interact with DCS and the effect of potential moderating variables. Data Sources: PubMed, EMBASE, and PsycINFO were searched from inception to February 10, 2016. Reference lists of previous reviews and meta-analyses and reports of randomized clinical trials were also checked. Study Selection: Studies were eligible for inclusion if they were (1) double-blind randomized clinical trials of DCS as an augmentation strategy for exposure-based cognitive behavior therapy and (2) conducted in humans diagnosed as having specific phobia, social anxiety disorder, panic disorder with or without agoraphobia, obsessive-compulsive disorder, or posttraumatic stress disorder. Data Extraction and Synthesis: Raw data were obtained from the authors and quality controlled. Data were ranked to ensure a consistent metric across studies (score range, 0-100). We used a 3-level multilevel model nesting repeated measures of outcomes within participants, who were nested within studies. Results: Individual participant data were obtained for 21 of 22 eligible trials, representing 1047 of 1073 eligible participants. When controlling for antidepressant use, participants receiving DCS showed greater improvement from pretreatment to posttreatment (mean difference, -3.62; 95% CI, -0.81 to -6.43; P = .01; d = -0.25) but not from pretreatment to midtreatment (mean difference, -1.66; 95% CI, -4.92 to 1.60; P = .32; d = -0.14) or from pretreatment to follow-up (mean difference, -2.98, 95% CI, -5.99 to 0.03; P = .05; d = -0.19). Additional analyses showed that participants assigned to DCS were associated with lower symptom severity than those assigned to placebo at posttreatment and at follow-up. Antidepressants did not moderate the effects of DCS. None of the prespecified patient-level or study-level moderators was associated with outcomes. Conclusions and Relevance: D-cycloserine is associated with a small augmentation effect on exposure-based therapy. This effect is not moderated by the concurrent use of antidepressants. Further research is needed to identify patient and/or therapy characteristics associated with DCS response.2018-05-0

Volatile and trace elements in basaltic glasses from Samoa : implications for water distribution in the mantle

Author Posting. © The Authors, 2005. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Earth and Planetary Science Letters 241 (2006): 932-951, doi:10.1016/j.epsl.2005.10.028.We report volatile (H2O, CO2, F, S, Cl) and trace element data for submarine alkalic basalt glasses from the three youngest Samoan volcanoes, Ta’u, Malumalu and Vailulu’u. Most samples are visibly sulfide saturated, so have likely lost some S during fractionation. Cl/K ratios (0.04 – 0.15) extend to higher values than pristine MORBs, but are suspected to be partly due to source differences since Cl/K roughly varies as a function of 87Sr/86Sr. There are no resolvable differences in the relative enrichment of F among sources, and compatibility of F during mantle melting is established to be nearly identical to Nd. Shallow degassing has affected CO2 in all samples, and H2O only in the most shallowly erupted samples from Vailulu’u. Absolute water contents are high for Samoa (0.63 – 1.50 wt%), but relative enrichment of water compared to equally incompatible trace elements (Ce, La) is low and falls entirely below normal MORB values. H2O/Ce (58 – 157) and H2O/La (120 – 350) correlate inversely with 87Sr/86Sr compositions (0.7045 – 0.7089). This leads us to believe that, because of very fast diffusion of hydrogen in mantle minerals, recycled lithospheric material with high initial water and trace element content will lose water to the drier ambient mantle during storage within the inner Earth. The net result is the counter-intuitive appearance of greater dehydration with greater mantle enrichment. We expect that subducted slabs will experience a two-stage dehydration history, first within subduction zones and then in the ambient mantle during long-term convective mixing

Top predators in relation to bathymetry, ice and krill during austral winter in Marguerite Bay, Antarctica

Author Posting. © Elsevier B.V., 2007. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part II: Topical Studies in Oceanography 55 (2008): 485-499, doi:10.1016/j.dsr2.2007.11.006.A key hypothesis guiding the U.S. Southern Ocean Global Ocean Ecosystems Dynamics (U.S. SO GLOBEC) program is that deep across-shelf troughs facilitate the transport of warm and nutrient-rich waters onto the continental shelf of the Western Antarctic Peninsula, resulting in enhanced winter production and prey availability to top predators. We tested aspects of this hypothesis during austral winter by assessing the distribution of the resident pack-ice top predators in relation to these deep across-shelf troughs and by investigating associations between top predators and their prey. Surveys were conducted July-August 2001 and August-September 2002 in Marguerite Bay, Antarctica, with a focus on the main across-shelf trough in the bay, Marguerite Trough. The common pack-ice seabird species were snow petrel (Pagodroma nivea, 1.2 individuals km-2), Antarctic petrel (Thalassoica antarctica, 0.3 individuals km-2), and Adélie penguin (Pygoscelis adeliae, 0.5 individuals km-2). The most common pack-ice pinniped was crabeater seal (Lobodon carcinophagus). During both winters, snow and Antarctic petrels were associated with low sea ice concentrations independent of Marguerite Trough, while Adélie penguins occurred in association with this trough. Krill concentrations, both shallow and deep, were also associated with Adélie penguin and snow petrel distributions. During both winters, crabeater seal occurrence was associated with deep krill concentrations and with regions of lower chlorophyll concentration. The area of lower chlorophyll concentrations occurred in an area with complex bathymetry close to land and heavy ice concentrations. Complex or unusual bathymetry via its influence on physical and biological processes appears to be one of the keys to understanding how top predators survive during the winter in this Antarctic region.This material is based upon work supported by the National Science Foundation under Grants No. OPP-9910096 (to C. Ribic), OPP-9910307 (to P. Wiebe), OPP-9632763, OPP-0120525, OPP-0217282 and OPP-0224727 (to W. Fraser), and a Fulbright Scholarship and Office of Naval Research Grant N00014-03-0212 (to G. Lawson)